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From:   Anders Roxell <anders.roxell@linaro.org>
To:     rafael@kernel.org, len.brown@intel.com, pavel@ucw.cz
Cc:     linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Anders Roxell <anders.roxell@linaro.org>
Subject: [PATCH] kernel: power: swap: fix sparse warnings
Date:   Thu,  7 Oct 2021 21:13:37 +0200
Message-Id: <20211007191337.540058-1-anders.roxell@linaro.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

When building the kernel with sparse enabled 'C=1' the following
warnings shows up:

kernel/power/swap.c:390:29: warning: incorrect type in assignment (different base types)
kernel/power/swap.c:390:29:    expected int ret
kernel/power/swap.c:390:29:    got restricted blk_status_t

This is due to function hib_wait_io() returns a 'blk_status_t' which is
a bitwise u8. Commit 5416da01ff6e ("PM: hibernate: Remove
blk_status_to_errno in hib_wait_io") seemed to have mixed up the return
type. However, the 4e4cbee93d56 ("block: switch bios to blk_status_t")
actually broke the behaviour by returning the wrong type.

Rework so function hib_wait_io() returns a 'int' instead of
'blk_status_t' and make sure to call function
blk_status_to_errno(hb->error)' when returning from function
hib_wait_io() a int gets returned.

Fixes: 4e4cbee93d56 ("block: switch bios to blk_status_t")
Fixes: 5416da01ff6e ("PM: hibernate: Remove blk_status_to_errno in hib_wait_io")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
---
 kernel/power/swap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 9ec418955556..47107f9cd14c 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -299,14 +299,14 @@ static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
 	return error;
 }
 
-static blk_status_t hib_wait_io(struct hib_bio_batch *hb)
+static int hib_wait_io(struct hib_bio_batch *hb)
 {
 	/*
 	 * We are relying on the behavior of blk_plug that a thread with
 	 * a plug will flush the plug list before sleeping.
 	 */
 	wait_event(hb->wait, atomic_read(&hb->count) == 0);
-	return hb->error;
+	return blk_status_to_errno(hb->error);
 }
 
 /*
-- 
2.33.0